From Connery to Pierce Brosnan and Daniel Craig, this preference is repeated again and again in 007 flicks. (Check out this video montage for the full Bond effect.)

So, its being the 50th anniversary of the first Bond movie and all, we wondered: Is there any scientific reason to prefer a martini that's mixed by shaking compared with one that's stirred? And, can you really taste the difference?

To answer these questions, we headed to Bar Dupont in Washington, D.C. — a kinda swanky joint where locals hang out.

We both came with theories (not our own theories, mind you, but rather ones we got from scientists — a little pre-research, you might say).

One idea is that perhaps Bond series author Ian Fleming had a strategic reason for shaking up his hero's drinks.

Our source, John Hayes of Penn State, says that since shaking a martini has a diluting effect on the drink, perhaps this was Fleming's way of keeping Bond's head in the game, even as he sipped a famously stiff cocktail.

The science behind this theory: When the martini is shaken, tiny bits of ice flake into the drink, and as they melt, the drink is diluted. (Also, bartenders usually slough off what's left in the stainless steel shaker, so maybe Bond was drinking less alcohol than we thought.) And, shaking tends to make the drink colder.

Or perhaps Fleming was in the know on the chemistry of shaken vs. stirred martinis.

"Shaking will better remove very volatile organic compounds from the liquid [alcohol]," explains George Christou of the University of Florida, "and air oxidizes some of the other organic compounds present, affecting its taste." This is akin to letting red wine breathe before you serve it, he says.

Christou also says some cheaper vodkas made from potatoes have some oil in them, and shaking will make an emulsion that will hide the oily taste — although it's hard to imagine Bond drinking cheap vodka.

So did we discern any difference?

After blinding ourselves with cloth napkins, we sipped on a couple of vodka martinis — one shaken and one stirred — that bartender Brian Collins mixed for us.

We were both able to tell right away which one was shaken. It was colder – not much colder – but just enough to notice.

But if we'd been asked to judge on the basis of taste alone? It would have been much harder. Honestly, picking up on the subtle taste influences of residual organics might require a supertaster.

Or someone who can reliably make a lucky guess.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

RENEE MONTAGNE, HOST:

We've regaled you with 007 moments this week, as we celebrate the 50th anniversary of James Bond films. Now we try to answer a question about Mr. Bond's taste in liquor. He had a particular way of ordering his martinis.

(SOUNDBITE OF MOVIE, "GOLDFINGER")

MAI LING: (Mei-Lei) Can I do something for you, Mr. Bond?

SEAN CONNERY: (as James Bond) Just a drink. A martini, shaken, not stirred.

MONTAGNE: So, are there any differences scientifically, between a shaken martini and one that is mixed by stirring? We sent NPR's Joe Palca and Allison Aubrey to Bar Dupont in D.C. to answer this question.

BRIAN COLLINS: And what will you be having today?

ALLISON AUBREY, BYLINE: Make that a dry martini, vodka - and shaken, not stirred.

COLLINS: Excellent.

AUBREY: And for the gentlemen?

JOE PALCA, BYLINE: Me too.

COLLINS: All right.

PALCA: When I found out we had this assignment, I thought can there really be a physical or chemical difference between a martinis that's shaken, not stirred.

AUBREY: I thought really probably there are ways to tell the difference in terms of how they look.

PALCA: Well, there are some physical reason is that you could actually say OK, this is different for a shaken martini and it is for a stirred martini.

AUBREY: So like actual chemistry differences?

PALCA: Chemistry and physics. And on the chemical front when chemicals in alcohol mixed with air, when you're shaking it up and you're getting sloppy, this air bubbles that are forming, if there's anything that's reactive, if there's anything that's still going to mix with oxygen, it will do it then. It's a little bit like wine grapes.

PALCA: So in the physics it would be that the heat transfer from the ice to the liquid is more efficient when you shake a martini. Because what you're doing is you're exchanging the cold that's in the ice cubes with the alcohol much more efficiently.

AUBREY: Ah, got it.

PALCA: So yes, it is more, a little bit of ice on the top sometimes, depending on whether the ice is flaking off or not.

AUBREY: Well, let's take this cooling effect one step further. I'd like to get into the realm of sensory science. So, you're talking about those little ice crystals making it colder, but as these tiny crystals melt, do you know what they're doing?

PALCA: What?

AUBREY: They're actually diluting the martini.

PALCA: Oh yeah, that makes sense. So why would you want a more dilute martini? I mean doesn't that defeat the purpose?

AUBREY: You know, that is a big question. My source thinks that maybe Ian Fleming thought about this and created Bond's preference for a shaken martini so that, you know, he could keep his head in the game. It looks like he was having the strong stiff drinks, when really the shaken might take the edge off a little bit.

COLLINS: I personally think so.

AUBREY: You think that's a good theory?

COLLINS: I think that's a good theory.

PALCA: Wow. (Unintelligible).

AUBREY: So my question is, you know, might we notice that difference? Might the burn a little bit less?

PALCA: Brian could make a stirred one and we could actually see if we could tell the difference.

AUBREY: What about if I blindfold you, you blindfold me, and then let Brian mix them up?

(LAUGHTER)

PALCA: I think - oh, we have napkins.

COLLINS: Let me save the glass ware here. All right. Here we go.

AUBREY: OK. We each get one here, one is shaken, one is stirred.

COLLINS: That's right.

AUBREY: All right. Cheers, Dr. Palca.

PALCA: Oh, yes.

(SOUNDBITE OF GLASSES CLINKING)

AUBREY: I've done the first one.

PALCA: I've got this.

AUBREY: All right.

PALCA: I'm already done. Can you tell the difference in this full slog?

AUBREY: In this sensory science.

PALCA: This sensory suggestion...

(LAUGHTER)

AUBREY: Let's try it. OK. I'm going to venture to say that the first one I tasted was shaken on the basis of temperature alone.

COLLINS: You are correct.

AUBREY: Oh, yes.

(LAUGHTER)

PALCA: I was going to say the same thing.

COLLINS: You are correct.

(LAUGHTER)

AUBREY: Awesome.

COLLINS: You two are good at this blindfold drinking martinis.

PALCA: OK. Spin them around again. Let's do this once again.

(LAUGHTER)

PALCA: Let's prove it wasn't a fluke. Best five out of 10, six out of four.